INTELIHEALTH - A long-term Brazilian study is helping to clarify factors that increase the risk of gum disease.

The study was done by researchers at the Federal University of Rio Grande do Sul in Porto Alegre. Researchers kept track of 653 people for 5 years. People in the study were at least 14 years old. All of them had at least 6 teeth.

More than one-third – 38% - of people in the study had gum (periodontal) disease that got worse over time. Dentists measured this by evaluating periodontal attachment loss. Healthy gums are firmly attached to teeth. As gum disease worsens, gums pull away from the teeth.

Certain groups were more likely to show worsening gum disease:

People older than 30 had twice the risk of younger people.

People with less education had 50% higher risk than those with more education.

Among people who had never smoked, males were 33% more likely than females to show worsening gum disease.

Compared with nonsmokers, both male and female smokers had a slightly increased risk. But the female smokers' risk was higher.

Race, income levels, patterns of dental care and diabetes were not linked with worsening gum disease over the five-year period.

The U.S. Centers for Disease Control and Prevention says that gum disease is more common in these U.S. groups:

Older people

Those with lower education levels

Men

Smokers

The CDC also says that Americans living in poverty are more likely to have periodontal disease. However, the Brazilian study did not show this.

The Brazilian study appears in the March issue of the Journal of Clinical Periodontology.